net: sched: cls: add extack support for delete callback

This patch adds extack support for classifier delete callback api. This
prepares to handle extack support inside each specific classifier
implementation.

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c
index 92d6838..55467c3 100644
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -316,7 +316,8 @@
 	kfree_rcu(head, rcu);
 }
 
-static int route4_delete(struct tcf_proto *tp, void *arg, bool *last)
+static int route4_delete(struct tcf_proto *tp, void *arg, bool *last,
+			 struct netlink_ext_ack *extack)
 {
 	struct route4_head *head = rtnl_dereference(tp->root);
 	struct route4_filter *f = arg;